Composition of matter and process of making the same



Patented Mar. 12,; 1935 1,993,750 COMPOSITION OF MATTER AND PROCESS OF MAKING THE SAME Harold Robert Ratton, Andovcr, Mala, assignor to Raffold Process Corporation, a corporation of Massachusetts No Drawing.

Original application March 15,

1928, Serial No. 262,030. Divided and this application August 27, 1930, Serial No. 478,285

25 Claims. ((1134-22) One object of my invention is to produce a new, useful, and improved sized paper made with a carbonate filler, and to providea simple method for accomplishing this result.

This is a division of my copending application Serial No. 262,030, filed March 15, 1928, now Patent No. 1,819,441, issued August 18, 1931.

Further objects are the employment of paraflin in manufacturing this paper; the use of this paraffin in emulsified form; the production of a complex between the emulsion and the carbonate filler; the avoidance of the difliculties heretofore existing when paraflin emulsions were employed in papermaking; the avoidance of the use of rosin; the production of a more age-re- -sistant paper; the productionof a paper which shows little discoloration with age; and other objects which will appear in the detailed description which follows.

When I use the expression carbonate filler" (or fillers) I mean the substantially water insoluble carbonates (normal or basic) of the alkaline earth metals (which expression is herein intended to include magnesium), or compounds, or double salts, or physically associated mixtures of these with one or more other acid soluble materials of a substantially water insoluble nature, these fillers whether simple or complex as above, being characterized by the fact that, when agitatedin contact with freshly boiled distilled water in concentrated suspension for say an hour, they impart to the water a pH value which is on the alkaline side of the neutral point, and also by the fact that they give off carbon dioxide gas when brought into contact'with an aqueous mineral acid, e. g. hydrochloric acid. Examples of such fillers are calcium carbonate, of which lime mud from the causticizing process is one form; calcium carbonate magnesium basic carbonate employed in the paper disclosed in my U. S. Patent No. 1,595,416 of August 10, 1926; and calcium carbonate magnesium hydroxide, disclosed in my U. S. Patent No. 1,415,391 of May 9, 1922, and used in the filled paper disclosed in my U. S. Patent No. 1,598,104 of August 91, 1926. Of course these fillers are referred to not only in their chemically pure form, but also in commercial form containing such impurities as may occur in such commercial products; and also when present with other material, so that they constitute only a part. either major or minor, of the whole. (one special case of which is described more fullyin the following paragraph). It should be stated that any given filler of the type referred to is not necessarily of uniform particle size; nor are the average particle sizes of the fillers necessarllyalike, as some of the fillers of the type referred to have relatively coarse grain particles, whereas others are much more finely divided, and some are so finely divided that they maybe said to approach or be in the colloidal condition.

Moreover when I use the expression carbonate filler" (or fillers) I mean to include not only the case where it is added as such to the heaters, or other similar or mixing or compounding or disintegrating or treating machine, but also the case where it may be added wholly or' in part incorporated with fibrous material and/or other material. Such a case would be where paper made with carbonate filler, either as a filling or coating constituent, or both, is reused in the papermaking process. Such papers may be those known to the trade as old papers or old waste papers or waste papers in any form, or returned trimmings or damaged paper or the like, or they may be the broke", that is, the partially made, the imperfect, or the waste paper which accompanies the papermaking, finishing, storing, packing, shipping, or the like operations in a paper mill, and which is reworked either in the same or some other mill. Such papers are sometimes reworked by themselves and added in broken down or in pulp form in the paper making process, being treated or cooked in some cases with or without chemicals, and washed it desired,this reworking meaning to include the process of deinking if such is practiced or of bleaching or of both deinking and bleaching, or sometimes they are added directly to the other paper making ingredients in the heater or similar or other mixing or compounding or disintegrating or treating machine, and broken up directly therein. In any event they are a source of carbonate filler in the paper to be made. and are included in the term carbonate filler (or fillers) as used herein.

when I employ the term paraflln" herein, I

mean paraflln wax, which is solid at ordinary or room temperature. I do not mean to restrict mysell only to the paramn hydrocarbons, but mean to include in this term all the hydrocarbons of a waxy nature substantially unsaponifiable and inert to acidic and alkaline materials under ordinary conditions of temperature and pressure, whether derived from petroleum, shale, lignite, earth wax, or other natural or artificial sources. I do not, however, mean to include in this term material of a pitchy nature.

When I usethe word paper" herein, I use it in the broad sense to include products of manufacture' of all types and of all weights and thicknesses, which contain as an essential constituent a considerable amount of prepared fibre and which are capable of being produced on a Fourdrinier, cylinder, or other forming, or felting, or shaping, or molding machine. i

The novelty of the present invention does not reside broadly in the production of a sized carbonate filled paper as a new article of manufacture, as such papers have been previously known: e. g., see Loshs British Patent No. 2664 of- 1859; Cappazas British Patent No. 5776 of 1899; Stathams U. S. Patent No. 1,209,221 of December 19, 1916;

and my U. s. Patents No. 1,595,416 of August 10,

1926, and No. 1,598,104 of August 31, 1926.

In some of the examples cited rosin is employed as the sizing agent. My invention, however, does not involve the use of rosin size, but on the other hand makes use, in a manner which is set forth fully below, of paraffin, preferably in a comminuted form commonly called an emulsion, (i. e., a suspension of minute discrete particles of parturn in a liquid, preferably aqueous or miscible with water), containing an emulsifying agent, (i. e., a material or materials which tend to prevent the coalescence of the discrete particles of parafiin). Such emulsions are well known and may be satisfactorily produced in a variety of ways, as e. g., in a dispersion machine, such as in one of a variety of colloid mills or homogenizers. An example of such an emulsion is parafiin emulsified in water with a sulphonated oil as emulsifying agent; another example is paraffin emulsified in water with ammonium oleate as emulsifying agent. Others will occur to those skilled in the art. In regard to the paraflin used, of course, either low or high melting point material can be employed. The so-called fully refined paraffin is entirely satisfactory because it does not impart objectionable color to white sheets. However, for purposes of economy, it is often desirable to use a less pure material and for instance such material as is known to the trade as a semi-refined parafiin scale, containing approximately l2% of oil and water as impurities, gives satisfactory results. Such material will perhaps in certain cases have varying melting points, but one particular sample used, for example, had a melting point of approximately 115 F. (46 0.). Other even more impure paraflins may be used, especially if the color (whiteness) requirements of the finished paper are not too exacting, or if papers. other than white, are to be made.

The use of femulsions of paraflin in paper is known butv this use has been directed mainly to the production of parafilned rather than to sized (i. e., resistant in varying degree to ordinary aqueous writing ink) paper, or at least to paper containing a relatively higher percentage of parafiin than that required for sizing in my process. Such papers may have a paraflin finish or be translucent or even transparent, and waterproof, but my paper does not partake of these characteristics, but is similar to, and by mere observation cannot be readily distinguished from, ordinary rosin sized filled papers.

However, to my knowledge, heretofore it has not been proposed to use parafiin emulsions as sizing agents with carbonate fillers, nor has the specific effect been noted when such employment is made, nor the unique use that can be made of such effect.

In some of the papers referred to above in which paraflin emulsions have been previously used, the paraffin is precipitated on the fibre while the fibre is in aqueous pulp condition, usually by alum, in discrete form so that the individual particles of paraffin are deposited from the emulsion on the fibre and coalesced by fusion on the driers of the paper machine. Parafiin is normally nonadhesive, incontradistinction to certainpitchy materials which are normally adhesive materials. When precipitated in minute discrete particles on the fibre, there is a tendency, however, for some of these patricles under the conditions of agitation obtaining in the papermaking process to become detached from the fibre, and such particles may be agglomerated by pressure or otherwise so that relatively coarse flakes or lumps of paraflin are formed and exist at the wet end of the paper machine. These may cause very serious trouble particularly with the screens and the wet end of the paper machine itself particularly with various parts of the machine clothing, and the press rolls.

In other cases where paraflin is used in emulsionform, the paraffin is adsorbed or absorbed on the fibre from an emulsion under very special conditions as to hydration,and in one case, under specific conditions as to acidity,-which do not obtain in ordinary paper making operations. The use of my method, however,'avoids the difficulties, and the necessity for use of special conditions, above mentioned. 1

I have discovered that a paraffin emulsion and an aqueous suspension of carbonate filler mutually fiocculate. one another and that this flocculate or complexof paraflin and carbonate filler does not partake of the nature of discrete particles of parafiin, is not broken down to discrete paraffin particles by mechanical action, and has no tendency to ball up and agglomerate as do unattached discrete particles of paraffin released from the emulsifed condition, and is not of such a nature as to adhere to the paper machine or machine clothing.

Ihave not sufficient evidence yet to be certain of the exact nature of the action taking place or of the product thereof and I therefore have named this combination or association of carbonate filler and parafiin, whether physical or chemical or both, a complex.

When such a complex, prepared by flocculation and the flocculated mass is separated from the supernatant liquid and then dried say at 100- 110 0., there is no evidence of melted parafiln, but on the contrary the flocculent complex dries out to a powdery mass, non-sticky and non-agglomerant whether hot or cold, and this complex may be seen by floating it on aqueous ink to possess ink resistant qualities. When the dried complex is gently heated in a crucible over a flame a vapor is driven off which has an odor similar to that of volatilized paraflin, and this vapor catches fire if a fiame'is juxtaposed. Moreover if another portion of this same complex before drying is subjected for say several minutes in a beaker in presence of water to a vigorous boiling, and the beaker cooled, no scum of paraffin is found to have separated to the surface, and no evidence of any separation of paraffin is noted. I have also found that if a definite quantity of a given emulsion be diluted, and successive quantities of a suspension of carbonate filler be added with agitation until all the emulsion has been fiocculated, that there seems to exist a stoichiometrical relation between the amoimt of paramn present and the amount of filler required to precipitate it, which is different for difierent carbonate fillers; e. g., with one emulsion it required approximately 2.4 parts of a certain sample of calcium carbonate magnesium hydroxide to flocculate substantially completely 1 part of parafiin in emulsified form, whereas with a certain sample of lime mud only .Gpartwasrequiredperlpartofparaflln. This is not advanced as an argument in favor of the chemical nature of the complex, as it is realized that certain physical conditions might also bring about a similar result.

, Furthermore it should be stated that this flocculation does not appear to be the result of the action of the carbonate filler with the emulsifying agent, as for example, although an ammonium oleate stabilized emulsion and calcium carbonate magnesium hydroxide mutually fiocculate one another, I have found that this carbonate filler has no noticeable fiocculatinz effect on this stabilizer'in the absence of the emulsified paraflin.

All the above is offered as evidence of the peculiarly stable nature of this novel carbonate filler-paramn complex which renders it particularly useful and satisfactory under the conditions under which it is employed.

As an example of the methodof practicing my invention I may place the fibrous pulp in the' beater, or other similar or compounding or mixing or distintegrating or treating machine, then add the parafiin emulslon,-a convenient way being in dilute form,-incorporate this thoroughly with the pulp, then add the carbonate filler, then starch if desired and/or alum (attention in this connection being directed to my copending application Serial No. 202,453, filed June 29, 192 now matured into Patent No. 1,831,928, issued November 17, 1931). The above order of addition is not essential. but a convenient and desirable one for several reasons: 1. It allows thorough incorporation of emulsion with the fibre before the formation of the carbonate filler-parafiin complex; 2. If the emulsion be one which is cracked or broken by alum, this action will be prevented by the prior formation of the carbonate filler-paraffin complex, Such cracking by alum would produce free-i. e., unemulsifiedparaflin in a form tending to agglomerate into specks or lumps, which would cause trouble on the paper machine.

In the case where broke and/or old papers,

containing carbonate filler (as discussed in detail above) is used as part of the furnish, it is advisable to add this part after the paramn emulsion has been thoroughly incorporated with the other fibrous ingredients. v.

It is advisable to use as stable an emulsion as feasible, this being particularly recommended in fin. Sometimes in such cases an otherwise less stable emulsion can be protec alkali, for example ammonia.

It is also desirable in adding the paraffln emulsion to adopt the usual practice in adding liquids in the paper making procedure, namely to pass aswith an may be used in practicing my invention, to produce for instance a filled sized book or magazine paper which will give an inktest", (i. e.,

the time required for an ordinary aqueous writing ink at room temperature to strike through a sample of paper when floated thereon) of from one up to several minutes or more, according to circumstances, is as follows:

Pounds Fibrous furnish (sulphite and soda) 1500 Emulsified paraflln, calculated as lbs. paraffin present (3% on total weight of fibre and filler)- 60 Calcium carbonate magnesium hydroxide- 500 Starch 50 Alum 75 Of course lesser amountsof paraflin emulsion may be used with lesser sizing effect. The figures' (lbs.) given above refer to air dry weights in all cases except the filler (calcium carbonate magnesium hydroxide), in which case the figure given refers to bone dry weight.

This furnish may be added to the heater in the ordinary way, and then subjected to the usual paper making procedure on a Fourdrinier, cylinder, or other forming, or felting, or shaping, or molding machine, and the paper finished in the usual manner, using the regular machines normally employed for the various processes. or of course special machines may be employed if desired. The resultant paper may be used for such purposes as those to which sized filled papers are normally put, including that as a raw stock for further conversion, as for example for coating. The carbonate filler in my paper, as is the filler in other filled papers, is distributed substantally uniformly throughout.

My paper has the distinct advantage of possessing age resisting qualities in '-a unique degree. It'is well known that acid conditions in papers are very detrimental to permanence:

0 such conditions are rendered imposible by the use of a carbonate filler. It is also well known that rosin sized papers discolor with age, and some authorities are of the opinion that the rosin acts catalytically in the oxidation and subsequent deterioration of the cellulosic content of the paper: the absence of rosin in y sized paper removes this undesirable discoloring and oxidizing agent, and the presence of paraffin substitutes in its stead a material noted for its extreme inertness, permanence, and resistance to oxidation. Thus by the combination of a carbonate filler and paraflin in paper, I have avoided in a unique manner theprincipal deteriorating effects which now tend to make paper less permanent, and have incorporated in the paper materials which mutually lend their assistance in rendering the paper more permanent and more age resisting. I

Such a permanent paper has of course a great advantage for purposes which require preservation of the paper. It also has a decided economic advantage, as certain papers, which in order to obtain permanency have heretofore been required to be made with all or a portion of the fibrous furnish consisting of particularly resistant cellulose as rag fiber, may now, because of the enhanced permanency arising from the carbonate filler--paraflin content, and the absence of rosin, be made with a lesser amount of resistant cellulose fibre, or in some cases, in the absence of such resistant fibre. This will result in economy in the manufacture of such papers, as the resistant celluloses are more expensive than the ordinary fibres substituted therefor.

By the term rosin as hereinafter employed I intend to include not only rosin but any compound thereof.

Whereas I have described several illustrative formulae, furnishes, procedures, and methods of operation, I do not intend to be limited thereby, as my invention may be practiced in a wide variety of ways, with wide variations of formulae, under a wide variety of conditions, and with a broad variety of raw materials, and various changes may be resorted to in the practice of my invention without departing from the spirit of my invention or the scope of the subjoined claims. Likewise I do not intend to be limited by any theory expressed herein as the scope of my invention is independent thereof.

In the claims, where I use the word compound, I mean one or more compounds of the kind indicated.

As pointed out above in defining carbonate filler, it is to be understood that this term is not intended to include substantially watersoluble materials. a

By polyvalent metal I mean metal having a.-

valence of more than one.

I claim:

1. A composition of matter comprising the flocculation product of the interaction of carbonate filler and parafiin emulsion.

2. A composition of matter comprising the flocculation product of the interaction of carbonate filler and paraflin emulsion in the absence of rosin.

3. A composition of matter comprising the flocculation product of the interaction of alkaline earth metal carbonate and paraffin emulsion.

4. A composition of matter comprising the flocculation product of the interaction of calcium carbonate and paraflln emulsion.

5. A composition of matter comprising the flocculation product of the interaction of calcium carbonate magnesium basic carbonate and parafiin emulsion.

6. A composition of matter comprising the flocculation product of the interaction of calcium carbonate magnesium hydroxide and paraffin emulsion.

7. A composition of matter in which carbonate filler is present in substantial amount comprising the flocculation product of the interaction of carbonate filler, paraffin emulsion, and substantially water soluble aluminum cox-.pound.

8. A composition of matter in which carbonate filler is present in substantial amount comprising the flocculation product of the interaction of alkaline earth metal carbonate, paraflin emulsion, and substantially water soluble aluminum 7 compound.

9. A composition of matter in which carbonate filler is present in substantial amount comprising the flocculation product of the interaction of calcium carbonate, paraffin emulsion, and substantially water soluble aluminum compound.

10. A composition of matter in which carbonate filler is present in substantial amount comprising the flocculation product of the interaction of calcium carbonate magnesium basic carbonate, paraflln emulsion, and substantially water soluble aluminum compound.

11. A composition of matter in which carbonate filler is present in substantial amount comprising the flocculation product of the interaction of calcium carbonate magnesium hydroxide, paraflin emulsion, and substantially water soluble aluminum compound.

12. A composition of matter in finely divided condition comprising carbonate filler the particles of which have a coating thereon comprising paraffin. and substantially water'insoluble aluminum soap.

13. The process of producing a composition of matter comprising mixing carbonate filler with paraffin emulsion.

14. The'process of producing a composition of matter in which carbonate filler is present in substantial amount comprising mixing carbonate filler with paraflin emulsion, and adding substantially water soluble compound of aluminum.

15. The process of producing a composition of matter in which carbonate filler is present in substantial amount comprising mixing carbonate filler with paraflin emulsion, and adding alum.

16. A composition of matter in finely divided condition comprising carbonate filler the particles of which have a coating comprising paraffin thereon and which is substantially miscible with water when produced, but substantially water repellent after it has been dried.

1'7. A filling composition in finely divided condition comprising carbonate filler the particles of which have a coating comprising paraffin thereon.

18. The process of producing a composition of matter in which carbonate fillervis present in substantial amount comprising mixing carbonate filler with paraflin emulsion, and adding substantially water soluble salt of a polyvalent metal.

19. A method of rendering finely divided calcium carbonate substantially less reactive with acidic material, which comprises treating such carbonate with' an aqueous emulsion of paraffin. 20. A method of making a product of manufacture which comprises providing in an aqueous medium materials comprising carbonate filler and substantially water insoluble sizing agent substantially unreactive in respect to said filler, the weight of said filler present being substantially greater than the weight of said agent present, and drying said mix.

21. A product of manufacture in substantially dry condition having the characteristics of having been derived from an aqueous mix comprising carbonate filler and a substantially water insoluble substantially water repellant agent substantially unreactive in respect to said filler, the weight of said filler present being substantially greater than the weight of said agent present.

22. A method of making a product of manufacture which comprises providing in an aqueous medium materials comprising carbonate filler,

substantially water insoluble sizing agent subneeaveo dry condition having the characteristics of having been derived from an aqueous mix comprising carbonate filler, substantially water insoluble substantially water repellent agent substantially unreactive in respect to said filler, the weight of said filler present being substantially greater than the weight of said agent present, and substantially water soluble salt of a polyvalent metal.

24. A new filling material comprising a carbonate filler composition in finely divided condition possessing reactivity with acidic material in substantially reduced degree in comparison with the carbonate filler content of said composition, said carbonate filler content comprising substantially the greater part by weight ofsaid carbonate filler composition.

25. As a new composition: an aqueous mix which comprises acidic material and a filling 'material comprising a carbonate filler composition in finely divided condition possessing reactivity with said acidic material in substantially reduced degree in comparison with the carvbonate filler content of said composition, said tent of said composition. 7

HAROLD ROBERT RAFION. 

